Figure 3. Map of the Caribbean showing the location of Caribbean ODP Sites 998, 999, and 1000 in relation to the two areas of the northern Nicaraguan Rise and the Isthmus of Panama that have played a critical role in the establishment of the modern ocean circulation. Tectonic activity has modified the bathymetry of these two areas. These modifications have influenced the general Atlantic circulation and, in particular, the southern/northern Caribbean and Atlantic/Pacific Ocean interchanges at various times during the middle and early late Miocene. CH = Cape Hatteras; V = Vema; EN = Endeavour.